This invention relates to an improved mechanism for attaching U-shaped clips about gathered material and more particularly to the improvement in single and double clipping mechanisms of a die block assembly having an elastically responsive characteristic.
One method of processing of comminuted meat or cheese products includes stuffing the product in a casing material and forming U-shaped metal clips about portions of gathered casing material at spaced intervals. U.S. Pat. No. 3,400,433 issued Sep. 10, 1968 entitled "Clipping Device" in the name of Klenz, describes a typical clip U.S. Pat. No. 4,004,339 issued Jan. 25, 1977 entitled "Single Piston Operated Clip Device" and reissued Jan. 22, 1980 as U.S. Pat. No. Re 30,196 in the name of Velarde, describes a typical device for fastening such clips about casing material. The clipping operation often includes simultaneously applying two clips to a portion of gathered material by a single piston operated mechanism as described in U.S. Pat. No. 4,001,926 issued Jan. 11, 1977 entitled "Double Clipper, Single Piston Operated Device" in the name of Velarde. Fastening straps may also be clipped to the gathered casing material in order to facilitate further processing of the product as described in U.S. Pat. No. 4,227,668 issued Oct. 14, 1980 entitled "Hanger Member" in the name of Ernst.
Variations in both the clipper mechanism component tolerances and the cross sectional area to be circumscribed by the clip affect the adequacy of attachment of the clip about the gathered material. A clip applied too tightly may impart undue pressure to the gathered casing material causing the fibers of the casing material to fracture. Conversely, a too loosely applied clip may slip off the casing material. To compensate for such circumstances, applicant provides means for adjusting the position of a die block which is engaged by a clip in response to driving forces imparted by a fixed stroke reciprocating punch as described in U.S. Pat. No. 4,458,402 issued Jul. 10, 1984 entitled "Adjustable Crimping Die for Clipper Mechanism". U.S. Pat. No. 4,458,402 employs a die block assembly that requires manual operation to adjust the position of the die block. The die block assembly compensates for variations in the cross sectional area about which the clip is applied and for component tolerances in the clipper mechanism. Variations in the cross sectional area about which the clip is applied may result from variations in gathered material bulk and/or from the addition of a fastening strap to the gathered material.
The present invention contemplates a construction which automatically and dynamically overcomes the problems noted with respect to manual repositioning of the die block to compensate for variations in the cross sectional area about which a clip is applied.